Gender specific femoral rasps

ABSTRACT

Rasps for preparing bones of various patients to receive a prosthetic implant and a method for using the same. Multiple rasps may be provided as a set. Within the set, the rasps generally correspond to the size and shape of a single prosthetic implant, such as a prosthetic femoral hip stem, and have a range of bone removal and bone compression capabilities to account for unique bone characteristics of the various patients. A surgeon may select a desired rasp from the set provided depending on the patient&#39;s unique bone characteristics.

CLAIM OF PRIORITY

This application is a continuation of U.S. patent application Ser. No.12/179,771, filed on Jul. 25, 2008, the benefit of priority of which isclaimed hereby, and which is incorporated by reference herein in itsentirety.

BACKGROUND

1. Field of the Invention

The present invention relates to rasps. More particularly, the presentinvention relates to rasps for preparing bones of various patients toreceive a prosthetic implant and to a method for using the same.

2. Description of the Related Art

Joint arthroplasty is a surgical procedure for replacing damagedcomponents of a joint with prosthetic components. Such damage may becaused by, for example, traumatic injury or some form of arthritis, suchas osteoarthritis. Joint arthroplasty may relieve pain and restoremotion in the damaged joint.

The hip joint is formed between the head of the femur and the acetabulumof the pelvis. Therefore, arthroplasty of the hip joint can involvereplacing the femoral head and/or the acetabulum with prostheticimplants. Replacing the femoral head, in particular, involves resectingthe femoral head along its neck and preparing the intramedullary canalof the femur to receive a prosthetic femoral hip stem. This prostheticfemoral hip stem will ultimately anchor a prosthetic femoral head.

Preparation of the intramedullary canal has a significant impact on theentire arthroplasty procedure. The prepared canal determines the fitbetween the prosthetic femoral hip stem and the femur, which in turndetermines the fit between the prosthetic femoral head and theacetabulum. For example, if the prepared canal is too large, gaps mayform between the prosthetic femoral hip stem and the femur, which couldcause shifting or rotation of the hip stem. Also, if the prepared canalis too large, the prosthetic femoral hip stem may be seated too deepwithin the femur, resulting in an unnatural placement of the prostheticfemoral head. On the other hand, if the prepared canal is too small, theprosthetic femoral hip stem may not be seated deep enough within thefemur, also resulting in an unnatural placement of the prostheticfemoral head.

Currently, surgeons have available in the operating room a single raspto prepare the intramedullary canals of each and every patient. Thissingle rasp corresponds to the size and shape of the prosthetic femoralhip stem to be implanted. However, each patient has unique bonecharacteristics, depending on, for instance, age, health, and gender.Typically, a younger male will have harder, more dense bone than anolder female. Therefore, the exact same rasp may result in differentlysized canals, depending on the patient's unique bone characteristics.More specifically, the rasp may produce a canal that is too small in apatient with hard, dense bone, while the rasp may produce a canal thatis too large in a patient with soft, weak bone.

SUMMARY

The present invention relates to rasps for preparing bones of variouspatients to receive a prosthetic implant and to a method for using thesame. Multiple rasps may be provided as a set. The rasps of the setgenerally correspond to the size and shape of a single prostheticimplant. Also, the rasps of the set range in aggressiveness to achievevarious levels of bone removal and bone compression to account forunique bone characteristics of various patients. The set may include amore aggressive rasp configured to achieve bone removal and a lessaggressive rasp configured to achieve bone compression rather than boneremoval. For example, a rasp may have sharp, pointed teeth to achievesignificant bone removal. Another rasp may have curved, rounded teeth toachieve bone removal, but to a lesser extent than the rasp with pointedteeth. Yet another rasp may have an essentially smooth face to achievebone compression rather than bone removal. Still yet another rasp mayinclude a groove set into its face to achieve less bone compression thanthe rasp having an essentially smooth face. A surgeon may select adesired rasp from the set provided depending on the patient's uniquebone characteristics.

According to an embodiment of the present invention, a rasp is providedfor preparing a bone femur to receive a prosthetic implant. The rasp hasan elongate body generally corresponding to the geometry of theprosthetic implant. The elongate body includes a plurality of teethextending therefrom. The elongate body also includes a medial face, alateral face, an anterior face, and a posterior face. The medial facehas a medial profile generally corresponding to a medial profile of theprosthetic implant, the lateral face has a lateral profile generallycorresponding to a lateral profile of the prosthetic implant, theanterior face has an anterior profile generally corresponding to ananterior profile of the prosthetic implant, and the posterior face has aposterior profile generally corresponding to a posterior profile of theprosthetic implant. At least one of the faces is essentially smooth,whereby the essentially smooth face lacks teeth extending therefrom.

According to another embodiment of the present invention, a set of raspsis provided for preparing a bone to receive a prosthetic implant. Theset includes a first rasp having a first elongate body and a second rasphaving a second elongate body. Both elongate bodies have a geometrygenerally corresponding to the geometry of the prosthetic implant. Thefirst elongate body includes a medial face having a medial profilegenerally corresponding to a medial profile of the prosthetic implant, alateral face having a lateral profile generally corresponding to alateral profile of the prosthetic implant, an anterior face having ananterior profile generally corresponding to an anterior profile of theprosthetic implant, and a posterior face having a posterior profilegenerally corresponding to a posterior profile of the prostheticimplant. The anterior face and the posterior face of the first elongatebody have at least one of an essentially smooth face, whereby theessentially smooth face lacks teeth extending therefrom, an essentiallysmooth face with a groove set into and interrupting the essentiallysmooth face, a plurality of pointed teeth extending therefrom, and aplurality of rounded teeth extending therefrom. Each pointed toothextends from the face to an end defined between two essentially planarportions of the pointed tooth. Each portion of the pointed tooth islocated within a plane, and the planes intersect along an axis. The endof the pointed tooth is located within approximately 0.05 millimeters ofthe axis. Each rounded tooth extends from the face to an end definedbetween two essentially planar portions of the rounded tooth. Eachportion of the rounded tooth is located within a plane, and the planesintersect along an axis. The end of the rounded tooth is located towarda longitudinal axis of the first elongate body more than approximately0.05 millimeters from the axis. The second elongate body includes amedial face having a medial profile generally corresponding to themedial profile of the prosthetic implant, a lateral face having alateral profile generally corresponding to the lateral profile of theprosthetic implant, an anterior face having an anterior profilegenerally corresponding to the anterior profile of the prostheticimplant, and a posterior face having a posterior profile generallycorresponding to the posterior profile of the prosthetic implant. Atleast one of the anterior face and the posterior face of the secondelongate body differs from the corresponding face of the first elongatebody.

According to yet another embodiment of the present invention, a set ofrasps is provided for preparing a bone to receive a prosthetic implant.The set includes a first rasp having a first elongate body and a secondrasp having a second elongate body, both elongate bodies having ageometry generally corresponding to the geometry of the prostheticimplant. The first elongate body includes a proximal end, a distal end,a medial face, a lateral face, an anterior face, and a posterior face. Alength of the first elongate body is defined between the proximal endand the distal end of the first elongate body, a width of the firstelongate body is defined between the medial face and the lateral face ofthe first elongate body, and a depth of the first elongate body isdefined between the anterior face and the posterior face of the firstelongate body. The second elongate body includes a proximal end, adistal end, a medial face, a lateral face, an anterior face, and aposterior face. A length of the second elongate body is defined betweenthe proximal end and the distal end of the second elongate body, a widthof the second elongate body is defined between the medial face and thelateral face of the second elongate body, and a depth of the secondelongate body is defined between the anterior face and the posteriorface of the second elongate body. The length of the second elongate bodycorresponds to the length of the first elongate body, and the width ofthe second elongate body corresponds to the width of the first elongatebody. Along at least a portion of the corresponding lengths, the depthof the first elongate body exceeds the depth of the second elongatebody, such that the first elongate body is configured to contact morebone than the second elongate body.

According to still yet another embodiment of the present invention, amethod is provided for preparing a surgical patient's bone to receive aprosthetic implant. The method involves providing at least a first rasphaving a first elongate body and a second rasp having a second elongatebody, both elongate bodies having a geometry generally corresponding tothe geometry of the prosthetic implant. Each elongate body includes aproximal end, a distal end, a medial face, a lateral face, an anteriorface, and a posterior face. A length of each elongate body is definedbetween the proximal end and the distal end of the elongate body. Awidth of each elongate body is defined between the medial face and thelateral face of the elongate body. A depth of each elongate body isdefined between the anterior face and the posterior face of the elongatebody. The length of the second elongate body corresponds to the lengthof the first elongate body, and the width of the second elongate bodycorresponds to the width of the first elongate body. Along at least aportion of the corresponding lengths, the depth of the second elongatebody exceeds the depth of the first elongate body, whereby the secondelongate body is configured to contact more bone than the first elongatebody. The method also involves rasping the patient's bone with one ofthe first rasp and the second rasp.

Advantageously, the present invention provides a rasp that allows asurgeon to compress, rather than cut away, the patient's bone. A rasp inthis form is especially useful in preparing the bone of a patient havingpoor bone strength. Also advantageously, by making available a set ofrasps, the present invention allows the surgeon to customize preparationof the patient's bone based upon the patient's bone strength.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an anterior plan view of a femoral rasp;

FIG. 1A is a lateral plan view of the femoral rasp of FIG. 1;

FIG. 2 is an anterior plan view of a femoral rasp of the presentinvention;

FIG. 2A is a cross-sectional view of the femoral rasp of FIG. 2, takenalong line A-A of FIG. 2;

FIG. 2B is a cross-sectional view of the femoral rasp of FIG. 2, takenalong line B-B of FIG. 2;

FIG. 2C is a partial elevational view of the femoral rasp of FIG. 2,taken along line C of FIG. 2;

FIG. 2D is a partial elevational view of the femoral rasp of FIG. 2,taken along lines D of FIG. 2;

FIG. 2E is a partial elevational view of the femoral rasp of FIG. 2,taken along line E of FIG. 2;

FIG. 2G is a partial elevational view of the femoral rasp of FIG. 2,taken along lines G of FIG. 2J;

FIG. 2H is a lateral plan view of the femoral rasp of FIG. 2, takenalong line H of FIG. 2;

FIG. 2J is a medial plan view of the femoral rasp of FIG. 2, taken alongline J of FIG. 2;

FIG. 3 is an anterior plan view of another femoral rasp of the presentinvention;

FIG. 3A is a cross-sectional view of the femoral rasp of FIG. 3, takenalong line A-A of FIG. 3;

FIG. 3B is a cross-sectional view of the femoral rasp of FIG. 3, takenalong line B-B of FIG. 3;

FIG. 3C is a partial elevational view of the femoral rasp of FIG. 3,taken along line C of FIG. 3;

FIG. 3D is a partial elevational view of the femoral rasp of FIG. 3,taken along lines D of FIG. 3;

FIG. 3E is a partial elevational view of the femoral rasp of FIG. 3,taken along line E of FIG. 3;

FIG. 3G is a partial elevational view of the femoral rasp of FIG. 3,taken along lines G of FIG. 3J;

FIG. 3H is a lateral plan view of the femoral rasp of FIG. 3, takenalong line H of FIG. 3;

FIG. 3J is a medial plan view of the femoral rasp of FIG. 3, taken alongline J of FIG. 3;

FIG. 4 is an anterior plan view of yet another femoral rasp of thepresent invention;

FIG. 4A is a cross-sectional view of the femoral rasp of FIG. 4, takenalong line A-A of FIG. 4;

FIG. 4B is a cross-sectional view of the femoral rasp of FIG. 4, takenalong line B-B of FIG. 4

FIG. 4C is a partial elevational view of the femoral rasp of FIG. 4,taken along line C of FIG. 4;

FIG. 4D is a partial elevational view of the femoral rasp of FIG. 4,taken along lines D of FIG. 4;

FIG. 4E is a partial elevational view of the femoral rasp of FIG. 4,taken along line E of FIG. 4;

FIG. 4H is a lateral plan view of the femoral rasp of FIG. 4, takenalong line H of FIG. 4;

FIG. 4J is a medial plan view of the femoral rasp of FIG. 4, taken alongline J of FIG. 4;

FIG. 5 is an anterior plan view of yet another femoral rasp of thepresent invention;

FIG. 5A is a cross-sectional view of the femoral rasp of FIG. 5, takenalong line A-A of FIG. 5;

FIG. 5B is a cross-sectional view of the femoral rasp of FIG. 5, takenalong line B-B of FIG. 5;

FIG. 5C is a partial elevational view of the femoral rasp of FIG. 5,taken along line C of FIG. 5;

FIG. 5D is a partial elevational view of the femoral rasp of FIG. 5,taken along lines D of FIG. 5;

FIG. 5E is a partial elevational view of the femoral rasp of FIG. 5,taken along line E of FIG. 5;

FIG. 5H is a lateral plan view of the femoral rasp of FIG. 5, takenalong line H of FIG. 5;

FIG. 5J is a medial plan view of the femoral rasp of FIG. 5, taken alongline J of FIG. 5;

FIG. 6 is an anterior plan view of yet another femoral rasp of thepresent invention;

FIG. 6A is a cross-sectional view of the femoral rasp of FIG. 6, takenalong line A-A of FIG. 6;

FIG. 6B is a cross-sectional view of the femoral rasp of FIG. 6, takenalong line B-B of FIG. 6;

FIG. 6C is a partial elevational view of the femoral rasp of FIG. 6,taken along line C of FIG. 6;

FIG. 6D is a partial elevational view of the femoral rasp of FIG. 6,taken along lines D of FIG. 6;

FIG. 6E is a partial elevational view of the femoral rasp of FIG. 6,taken along line E of FIG. 6;

FIG. 6H is a lateral plan view of the femoral rasp of FIG. 6, takenalong line H of FIG. 6;

FIG. 6J is a medial plan view of the femoral rasp of FIG. 6, taken alongline J of FIG. 6;

FIG. 7 is a partial cross-sectional view of a right femur containing thefemoral rasp of FIG. 2;

FIG. 8 is a cross-sectional view of the femur and femoral rasp of FIG.7, taken along line 8-8 of FIG. 7;

FIG. 9A is an elevational view of an embodiment of teeth extending froma femoral rasp of the present invention;

FIG. 9B is an elevational view of another embodiment of teeth extendingfrom a femoral rasp of the present invention;

FIG. 9C is an elevational view of yet another embodiment of teethextending from a femoral rasp of the present invention; and

FIG. 10 is a partial cross-sectional view of a right femur containing aprosthetic femoral hip stem.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate exemplary embodiments of the invention and suchexemplifications are not to be construed as limiting the scope of theinvention any manner.

DETAILED DESCRIPTION

Referring to FIGS. 7-8, a rasp of the present invention is shown in theform of femoral rasp 10A within femur 12. The head of femur 12 has beenresected from proximal end 14 of femur 12 in preparation for receiving aprosthetic implant in the form of prosthetic femoral hip stem 100 (FIG.10) that will ultimately anchor a prosthetic femoral head (not shown).Femur 12 includes a soft, spongy layer of trabecular or cancellous bone16 surrounded by a stronger layer of cortical bone 18. Femur 12 is along, cylindrical bone that includes medial portion 20, lateral portion22, anterior portion 24, and posterior portion 26. Intramedullary canal28 extends the length of femur 12 between medial portion 20, lateralportion 22, anterior portion 24, and posterior portion 26. Although therasp is described and depicted herein as a femoral rasp configured toprepare a cavity in a femur, the present invention is generallyapplicable to any device configured to prepare a cavity in trabecular orcancellous bone, such as trabecular or cancellous bone of a tibia or ahumerus, for example. Similarly, although the prosthetic implant isdescribed and depicted herein as a prosthetic femoral hip stem, thepresent invention is generally applicable to any prosthetic implantconfigured to be worked into a cavity in trabecular or cancellous bone,such as a shaft of a tibial plate, for example.

Referring generally to FIGS. 2-6, rasps 10A-10E of the present inventionare illustrated. Referring in particular to FIGS. 2-2J, rasp 10Aincludes elongate body 30A that generally corresponds to the geometry ofprosthetic femoral hip stem 100 to be implanted into femur 12 (FIG. 10).Elongate body 30A extends between proximal end 32A and distal end 34A,and elongate body 30A narrows from proximal end 32A to distal end 34A.Elongate body 30A includes medial face 36A, lateral face 38A, anteriorface 40A, and posterior face 42A. As used herein, anterior, posterior,lateral, and medial are determined by the intended use of the rasp to aperson having ordinary skill in the art. As shown in FIG. 2A, thesefaces combine to form elongate body 30A having a trapezoidal crosssection. Medial face 36A extends parallel to lateral face 38A, andanterior face 40A is equal in length to posterior face 42A. The width ofelongate body 30A, or the distance between medial face 36A and lateralface 38A, exceeds the depth of elongate body 30A, or the distancebetween anterior face 40A and posterior face 42A. Rasps 10B-10E areillustrated in FIGS. 3-6 and are labeled with reference numeralscorresponding to those of rasp 10A. Rasps 10B-10E generally correspondto the geometry of the same prosthetic femoral hip stem 100 (FIG. 10) asrasp 10A.

A femoral rasp generally corresponds to the geometry of a prostheticfemoral hip stem if an outer geometry of the femoral rasp issubstantially congruent with an outer geometry of the prosthetic femoralhip stem. The femoral rasp need not be entirely congruent with theprosthetic femoral hip stem. For example, if the prosthetic femoral hipstem will be press fit into femur 12, the outer geometry of the femoralrasp will closely match the outer geometry of the prosthetic femoral hipstem. On the other hand, if the prosthetic femoral hip stem will becemented into femur 12, the outer geometry of the femoral rasp willslightly exceed the outer geometry of the prosthetic femoral hip stem toclear away enough space for a cement mantle to surround the prostheticfemoral hip stem upon implantation. It is also understood that the outergeometry of the femoral rasp may closely match the outer geometry of theprosthetic femoral hip stem in some locations, but not others, to clearaway enough space for the cement mantle in certain desired locations.

As shown in FIGS. 2-6, rasps 10A-10E of the present invention includehandle 44. Handle 44 extends from elongate bodies 30A-30E, and morespecifically from proximal ends 32A-32E of elongate bodies 30A-30E.Handle 44 provides a location to grip rasps 10A-10E while preparingintramedullary canal 28 of femur 12 (FIG. 7). Handle 44 and elongatebodies 30A-30E may be formed as a single, unitary object, or handle 44may be a separate piece that is attached to elongate bodies 30A-30E. Foradditional stability, handle 44 may be embedded into elongate bodies30A-30E.

Referring again to FIGS. 7-8, during use of rasp 10A to prepareintramedullary canal 28 of femur 12, the respective faces of elongatebody 30A correspond to respective portions of femur 12. Specifically,medial face 36A of elongate body 30A corresponds to medial portion 20 offemur 12, lateral face 38A of elongate body 30A corresponds to lateralportion 22 of femur 12, anterior face 40A of elongate body 30Acorresponds to anterior portion 24 of femur 12, and posterior face 42Aof elongate body 30A corresponds to posterior portion 26 of femur 12.Because the width of elongate body 30A exceeds its depth, rasp 10A willcut deeper into medial portion 20 and lateral portion 22 of femur 12 ascompared to anterior portion 24 and posterior portion 26 of femur 12.Therefore, medial face 36A and lateral face 38A of elongate body 30A maycontact primarily hard cortical bone 18, while anterior face 40A andposterior face 42A of elongate body 30A may contact primarily softtrabecular bone 16. Rasps 10B-10E of FIGS. 3-6 may also be used toprepare intramedullary canal 28 of femur 12. The respective faces ofelongate bodies 30B-30E of rasps 10B-10E would correspond to respectiveportions of femur 12 as set forth above with respect to rasp 10A.

Referring back to FIGS. 2-6, rasps 10A-10E of the present inventioninclude a plurality of teeth 46. Teeth 46 extend from elongate bodies30A-30E, and more specifically from medial faces 36A-36E, lateral faces38A-38E, anterior faces 40A-40E, and/or posterior faces 42A-42E ofelongate bodies 30A-30E.

Referring next to FIGS. 9A-9C, each tooth 46 extends outward distance Xfrom elongate body 30 until reaching end 48 at a location furthest fromthe corresponding face of elongate body 30. As used herein, tooth 46includes any projection from elongate body 30 in which distance X isgreater than or equal to approximately 0.5 millimeters. Distance X maybe as large as approximately 1.0 millimeter or 1.5 millimeters, forexample. Adjacent teeth 46 are spaced apart by distance Y. In otherwords, distance Y is equivalent to the distance between ends 48 ofadjacent teeth 46. Distance Y may be as small as approximately 1.0millimeter, 1.5 millimeters, or 2.0 millimeters or as large asapproximately 2.5 millimeters, 3.0 millimeters, or more, for example.Distances X and Y impact the amount of bone cut away by teeth 46. Forexample, as distance X increases, teeth 46 project further away fromelongate body 30 and further into the bone. According to an exemplaryembodiment of the present invention, a ratio of distance X to distance Yfor each tooth 46 may range between 1:2 and 1:3, for example.

Referring still to FIGS. 9A-9C, the shape of teeth 46, and in particularends 48, also impacts the amount of bone cut away by teeth 46. Eachtooth 46 includes two essentially planar portions, referred to herein astop portion 46′ and bottom portion 46″. It is within the scope of thepresent invention that essentially planar top portion 46′ and bottomportion 46″ of tooth 46 may be partially or entirely arcuate. As shownin FIGS. 9A-9C, top portion 46′ extends distally from elongate body 30toward bottom portion 46″ at an acute angle from a longitudinal axis ofelongate body 30. For example, top portion 46′ may extend distally fromelongate body 30 toward bottom portion 46″ at an angle of approximately30 degrees from the longitudinal axis. Bottom portion 46″ extends fromelongate body 30 generally perpendicularly to the longitudinal axis ofelongate body 30. The planes containing top portion 46′ and bottomportion 46″ intersect along axis 47. End 48 of tooth 46 is definedbetween top portion 46′ and bottom portion 46″ and is spaced distance Zfrom axis 47.

In one form of the present invention, illustrated in FIG. 9A, end 48 ispointed. As used herein, end 48 of tooth 46 is “pointed” when distance Zis less than or equal to approximately 0.05 millimeters. Therefore, iftop portion 46′ and bottom portion 46″ of tooth 46 extend nearly to axis47, such that end 48 forms within 0.05 millimeters of axis 47, tooth 46is considered pointed. Tooth 46 may also be considered pointed if topportion 46′ and bottom portion 46″ of tooth 46 extend slightly beyondaxis 47, such that end 48 forms within 0.05 millimeters of axis 47.

In another form of the present invention, illustrated in FIGS. 9B-9C,end 48 is rounded. As used herein, end 48 of tooth 46 is “rounded” whenend 48 fails to extend to axis 47 and distance Z is greater thanapproximately 0.05 millimeters. End 48 may be a linear segment of tooth46 joining top portion 46′ and bottom portion 46″, or end 48 may be acurved segment of tooth 46 having a radius of curvature R. In anexemplary embodiment of the present invention, radius of curvature Rapproaches infinity between top portion 46′ and bottom portion 46″, andradii of curvature R′ and R″ decrease as end 48 joins top portion 46′and bottom portion 46″, respectively.

Referring still to FIGS. 2-6, rasps 10A-10E are provided with elongatebodies 30A-30E having identical medial faces 36A-36E and identicallateral faces 38A-38E. As shown in FIGS. 2J, 3J, 4J, 5J, and 6J, medialfaces 36A-36E of elongate bodies 30A-30E include teeth 46 having sharp,pointed ends 48. As shown by comparing FIGS. 2E and 2D, teeth 46 arespaced closer together near proximal end 32A of elongate body 30A (FIG.2E) than near distal end 34A of elongate body 30A (FIG. 2D). In otherwords, distance Y may increase from proximal end 32A to distal end 34A.This varied distance Y is also illustrated in FIGS. 3D-3E, 4D-4E, 5D-5E,and 6D-6E for rasps 10B-10E. As shown in FIGS. 2H, 3H, 4H, 5H, and 6H,lateral faces 38A-38E of elongate bodies 30A-30E also include teeth 46having sharp, pointed ends 48. As shown by comparing FIGS. 2C and 2D,teeth 46 extend outward from lateral face 38A more near proximal end 32Aof elongate body 30A (FIG. 2C) than near distal end 34A of elongate body30A (FIG. 2D). In other words, distance X may decrease from proximal end32 to distal end 34. This varied distance X is also illustrated in FIGS.3C-3D, 4C-4D, 5C-5D, and 6C-6D for rasps 10B-10E.

Referring still to FIGS. 2-6, rasps 10A-10E are provided with elongatebodies 30A-30E having different anterior faces 40A-40E and differentposterior faces 42A-42E. As discussed above and as illustrated in FIG.8, anterior and posterior faces, 40A and 42A, of rasp 10A may contactmore trabecular bone 16 of femur 12 than medial and lateral faces, 36Aand 38A, of rasp 10A, which may contact more cortical bone 18 of femur12. Additionally, the strength of bone varies from patient to patientdepending on, for example, each patient's age, health, and gender. Forexample, it has been observed that in females, and particularly infemales with osteoporosis, intramedullary canal 28 tends to widen inanterior portion 24 and posterior portion 26 of femur 12, resulting inweakened anterior portion 24 and posterior portion 26 of femur 12compared to medial portion 20 and lateral portion 22 of femur 12.Therefore, in an exemplary embodiment of the present invention, rasps10A-10E are provided having various anterior faces 40A-40E and variousposterior faces 42A-42E. However, the following discussion is not to belimited to anterior and posterior faces, 40A-40E and 42A-42E, ofelongate bodies 30A-30E. In accordance with the teachings herein, thefollowing discussion may be adapted to medial faces 36A-36E and/orlateral faces 38A-38E of elongate bodies 30A-30E.

According to an embodiment of the present invention, illustrated inFIGS. 2-2J, anterior face 40A and posterior face 42A of elongate body30A include teeth 46 having sharp, pointed ends 48. In this embodiment,anterior face 40A and posterior face 42A are similar to medial face 36Aand lateral face 38A, all having teeth 46 with sharp, pointed ends 48.Teeth 46 on anterior and posterior faces, 40A and 42A, are shown indetail in FIG. 2G. In this form, rasp 10A is capable of cutting away asignificant amount of bone from anterior portion 24 and posteriorportion 26 of femur 12.

According to another embodiment of the present invention, illustrated inFIGS. 3-3J, anterior face 40B and posterior face 42B of elongate body30B include teeth 46 having curved, rounded ends 48. Teeth 46 onanterior and posterior faces, 40B and 42B, are shown in detail in FIG.3G. In this form, rasp 10B is capable of cutting away bone from anteriorportion 24 and posterior portion 26 of femur 12, but not as much bone asthe prior embodiment of rasp 10A (FIG. 2) having teeth 46 with sharp,pointed ends 48.

According to yet another embodiment of the present invention,illustrated in FIGS. 4-4J, anterior face 40C and posterior face 42C ofelongate body 30C are essentially smooth. As used herein, “essentiallysmooth” means that the face of elongate body 30C lacks teeth 46extending therefrom. In this form, rasp 10C will compress bone inanterior portion 24 and posterior portion 26 of femur 12 rather thancutting away bone.

According to still yet another embodiment of the present invention,illustrated in FIGS. 5-5J, anterior face 40D and posterior face 42D ofelongate body 30D include several grooves 50 that extend into elongatebody 30D. In this form, rasp 10D will compress bone in anterior portion24 and posterior portion 26 of femur 12 rather than cutting away bone.Due to grooves 50 being set back from anterior face 40D and posteriorface 42D of elongate body 30D, rasp 10D may compress even less bone thanrasp 10C (FIG. 4) because rasp 10D is more narrow than rasp 10C alonggroove 50. More specifically, the depth of rasp 10D, or the distancebetween anterior face 40D and posterior face 42D, along groove 50 isless than the depth of rasp 10C, or the distance between anterior face40C and posterior face 42C (FIG. 4), without groove 50.

According to still yet another embodiment of the present invention,illustrated in FIGS. 6-6J, anterior face 40E and posterior face 42E ofelongate body 30E include grooves 50 that extend into elongate body 30Eand span the length of elongate body 30E. Specifically, grooves 50 inthis embodiment span anterior face 40E and posterior face 42E ofelongate body 30E. In this form, rasp 10E will compress bone in anteriorportion 24 and posterior portion 26 of femur 12 rather than cutting awaybone. Due to grooves 50 spanning anterior face 40E and posterior face42E of elongate body 30E, rasp 10E may compress even less bone than rasp10D (FIG. 5) because rasp 10E is more narrow than rasp 10D across nearlythe entire length of rasp 10E.

This disclosure is intended to cover combinations and adaptations of theembodiments discussed above. For example, it is within the scope of thisdisclosure that medial face 36 and/or lateral face 38 of elongate body30 may include teeth 46 having curved, rounded ends 48. Similarly, it iswithin the scope of this disclosure that medial face 36 and/or lateralface 38 of elongate body 30, or at least a portion thereof, may beessentially smooth. It is also within the scope of this disclosure thatanterior face 40 may differ from posterior face 42 of elongate body 30.For example, anterior face 40 may be essentially smooth, while posteriorface 42 may include several grooves 50. It is also within the scope ofthis disclosure that medial face 36, lateral face 38, anterior face 40,and/or posterior face 42 of elongate body 30 may vary along a length ofthe rasp between the proximal end and the distal end of the rasp.

According to an embodiment of the present invention, a set of more thanone rasp may be provided, each rasp having unique features. The rasps ofthe set may be configured, suited, and intended to be used to prepare abone for the implantation of one and the same prosthetic implant.Therefore, the rasps of the set may have identical basic geometries, butthe rasps may have different cutting properties. The cutting propertiesof the rasps may be determined by, for example, the presence, elevation,number, sharpness, and/or pointedness, of cutting elements or teeth.These varied cutting properties within the set are purposeful,systematic, and intentional, as opposed to arbitrary differences incutting properties that may result from wear and/or manufacturingtolerances.

In an exemplary embodiment, the set includes numerous rasps that rangein aggressiveness to achieve various levels of bone removal and bonecompression to account for unique bone characteristics of variouspatients, such as rasps 10A-10E illustrated in FIGS. 2-6. For example,the set may include a more aggressive rasp configured to achieve boneremoval, such as rasp 10A having sharp, pointed teeth 46 (FIG. 2) orrasp 10B having curved, rounded teeth 46 (FIG. 3). The set may alsoinclude a less aggressive rasp configured to achieve bone compressionrather than bone removal, such as rasp 10C having essentially smoothsurfaces (FIG. 4) or rasp 10D or 10E having grooves 50 (FIGS. 5-6).

In another exemplary embodiment, the set includes at least a first raspand a second rasp. The first rasp may have a more aggressive cuttingsurface than the second rasp, at least over a portion of thecorresponding cutting surfaces. The second rasp may have a cuttingsurface that varies from the aggressive cutting surface of the firstrasp, at least over the corresponding portion of the second rasp. Forexample, over at least corresponding portions of the first and secondrasps, the first rasp may have cutting elements of higher elevation thanthe cutting elements of the second rasp. As another example, over atleast corresponding portions of the first and second rasps, the firstrasp may have more cutting elements than the second rasp. As yet anotherexample, over at least corresponding portions of the first and secondrasps, the first rasp may include cutting elements, and the second raspmay include an essentially smooth surface and/or an essentially smoothsurface with grooves set therein. Further ways to vary the cuttingproperties of the first and second rasps are described throughout thisspecification and the claims.

In yet another exemplary embodiment, the set includes at least a firstrasp and a second rasp. Each rasp includes faces and edges definedbetween the faces, such as medial face 36A, lateral face 38A, anteriorface 40A, and posterior face 42A of rasp 10A and the edges definedbetween those faces (FIG. 2). The cutting properties of the first andsecond rasps may be essentially identical at the edges, but the cuttingproperties may vary over at least a portion of corresponding faces. Forexample, the first and second rasps may have identical cuttingproperties at their edges, but the first rasp may have a more aggressivecutting surface than the second rasp, at least over a portion of thecorresponding faces. In a further exemplary embodiment, the first raspmay have a more aggressive anterior and/or posterior cutting surfacethan the second rasp, at least over a portion of the correspondingfaces, while the first and second rasps may have identical cuttingproperties over corresponding portions of their lateral and/or medialfaces.

In still yet another exemplary embodiment, the set includes at least afirst rasp and a second rasp. The cutting properties of the first andsecond rasps may be essentially identical over portions of the raspsintended to cut cortical bone. However, the cutting properties of thefirst and second rasps may vary, at least in part, over portions of therasps intended to cut cancellous or trabecular bone.

Referring to FIGS. 7-8, a method is provided for using rasp 10 toprepare intramedullary canal 28 of a patient's femur 12. A first step ofthe present method involves providing a set of more than one rasp, asdescribed in more detail above. Each rasp of the set may differ from theothers. In an exemplary form of the present method, the set includesnumerous rasps having a range of bone removal and bone compressioncapabilities, such as rasps 10A-10E illustrated in FIGS. 2-6.

Another step of the present method involves evaluating the strength ofthe patient's bones. The surgeon may perform a physical evaluation ofthe patient's bones, or base his determination of bone strength on thepatient's age, health, gender, or any other relevant factors. Forexample, the surgeon may determine that a younger male patient will haveharder, more dense bone than an older female patient.

After the surgeon has evaluated the strength of the patient's bones, thepresent method involves selecting a desired rasp from the set providedbased upon the needs of the patient. In an exemplary form of the presentmethod, this step involves selecting a desired rasp from a set thatincludes numerous rasps having a range of bone removal and bonecompression capabilities, such as rasps 10A-10E illustrated in FIGS.2-6. Therefore, the surgeon may select a desired rasp based upon thestrength of a particular patient's bones and the amount of bone removaland/or bone compression necessary to prepare femur 12. For example, ifthe patient has strong bones or high bone density, the surgeon may needto cut away bone from femur 12 to prepare intramedullary canal 28 (FIGS.7-8). Attempting to prepare intramedullary canal 28 in strong bone usingan essentially smooth rasp 10C (FIG. 4) would be difficult. Therefore,the surgeon could select from the set rasp 10A having sharp, pointedteeth 46 (FIG. 2) or rasp 10B having curved, rounded teeth 46 (FIG. 3).On the other hand, if the patient has weak bones or low bone density,the surgeon may need to compress bone in femur 12 to prepareintramedullary canal 28 (FIGS. 7-8). By compressing or compacting bonein femur 12, prosthetic femoral hip stem 100 (FIG. 10) may be surroundedby bone that is actually stronger than it was prior to rasping. Cuttingaway this soft bone, rather than compressing it, could remove too muchbone from femur 12, resulting in prepared intramedullary canal 28 thatis too large for prosthetic femoral hip stem 100 (FIG. 10). Therefore,the surgeon could select from the set rasp 10C having essentially smoothsurfaces (FIG. 4) or rasp 10D or 10E having grooves 50 (FIGS. 5-6).Advantageously, this exemplary embodiment allows a surgeon to customizepreparation of femur 12 to the needs of a particular patient.

Referring again to FIGS. 7-8, another step of the present methodinvolves rasping intramedullary canal 28 of the patient's femur 12 withthe desired rasp, illustrated as rasp 10A. First, the surgeon orientsrasp 10A with respect to femur 12 such that medial face 36A of elongatebody 30A corresponds to medial portion 20 of femur 12, lateral face 38Aof elongate body 30A corresponds to lateral portion 22 of femur 12,anterior face 40A of elongate body 30A corresponds to anterior portion24 of femur 12, and posterior face 42A of elongate body 30A correspondsto posterior portion 26 of femur 12. Next, distal end 34A of rasp 10A isdriven into femur 12, which may require the use of a tool such as ahammer. Then, the surgeon grips handle 44 and moves rasp 10A up and downin a sawing motion within femur 12 until rasp 10A is seated sufficientlydeep within femur 12. Finally, rasp 10A is removed from femur 12.According to an exemplary embodiment of the present invention, anteriorface 40A and posterior face 42A contact primarily trabecular bone 16 offemur 12, while medial face 36A and lateral face 38A contact primarilycortical bone 18 of femur 12.

Referring to FIG. 10, a final step of the present method involvesimplanting prosthetic femoral hip stem 100 into the preparedintramedullary canal 28 of the patient's femur 12. By providing a set ofrasps as set forth above, the prosthetic implant should fit securely inthe bone, such as by press-fit, independent of the patient's unique bonecharacteristics and bone quality. For example, prosthetic femoral hipstem 100 should fit securely into the prepared intramedullary canal 28of femur 12. Proper placement of prosthetic femoral hip stem 100 isnecessary for proper placement of the prosthetic femoral head (notshown), and proper placement of the prosthetic femoral head is necessaryto achieve natural interaction with the acetabulum (not shown).Prosthetic femoral hip stem 100 itself may be designed to accommodatethe patient's particular anatomy and bone strength, depending on, forexample, the patient's age, health, and gender. Examples of suchprosthetic femoral hip stems are described in U.S. patent applicationSer. No. 12/028,377, entitled PROSTHETIC HIP IMPLANTS, filed on Feb. 8,2008, U.S. patent application Ser. No. 11/687,862, entitled PROSTHETICHIP IMPLANTS, filed on Mar. 19, 2007, and U.S. Provisional PatentApplication Ser. No. 60/783,880, entitled PROSTHETIC HIP IMPLANTS, filedon Mar. 20, 2006, the disclosures of which are hereby expresslyincorporated herein by reference.

While this invention has been described as having preferred designs, thepresent invention can be further modified within the spirit and scope ofthis disclosure. This application is therefore intended to cover anyvariations, uses, or adaptations of the invention using its generalprinciples. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains and which fallwithin the limits of the appended claims.

What is claimed is:
 1. A method of preparing a surgical patient's boneto receive a prosthetic implant, the method comprising the steps of:providing at least a first rasp having a first elongate body with ageometry generally corresponding to the geometry of the prostheticimplant and a second rasp having a second elongate body with a geometrygenerally corresponding to the geometry of the prosthetic implant, eachelongate body comprising a proximal end, a distal end, a medial face, alateral face, an anterior face, and a posterior face, a length of eachelongate body defined between the proximal end and the distal end of theelongate body, a width of each elongate body defined between the medialface and the lateral face of the elongate body, and a depth of eachelongate body defined between the anterior face and the posterior faceof the elongate body, the length of the second elongate bodycorresponding to the length of the first elongate body, the width of thesecond elongate body corresponding to the width of the first elongatebody, and, along at least a portion of the corresponding lengths, thedepth of the second elongate body exceeding the depth of the firstelongate body, whereby the second elongate body is configured to contactmore bone than the first elongate body; and rasping the patient's bonewith one of the first rasp and the second rasp.
 2. The method of claim1, wherein the step of providing the first rasp and the second raspcomprises: providing the first rasp having a plurality of teethextending from at least one of the medial face and the lateral face ofthe first elongate body; and providing the second rasp having aplurality of teeth extending from at least one of the medial face andthe lateral face of the second elongate body.
 3. The method of claim 1,wherein the step of providing the first rasp comprises providing thefirst rasp having at least one essentially smooth face, whereby the atleast one essentially smooth face lacks teeth extending therefrom. 4.The method of claim 1, wherein the step of providing the second raspcomprises providing a second rasp having a plurality of teeth extendingfrom at least one of the anterior face and the posterior face of thesecond elongate body.
 5. The method of claim 4, wherein each toothextends from the at least one face to an end defined between twoessentially planar portions of the tooth, each portion of the toothlocated within a plane, the planes intersecting along an axis, the endof the tooth being located approximately 0.05 millimeters or less fromthe axis.
 6. The method of claim 4, wherein each tooth extends from theat least one face to an end defined between two essentially planarportions of the tooth, each portion of the tooth located within a plane,the planes intersecting along an axis, the end of the tooth beinglocated toward a longitudinal axis of the second rasp more thanapproximately 0.05 millimeters from the axis.
 7. The method of claim 1,wherein the step of providing at least the first rasp and the secondrasp further comprises providing a third rasp having a third elongatebody with a geometry generally corresponding to the geometry of theprosthetic implant, the third elongate body comprising a proximal end, adistal end, a medial face, a lateral face, an anterior face, and aposterior face, a length of the third elongate body defined between theproximal end and the distal end of the third elongate body, a width ofthe third elongate body defined between the medial face and the lateralface of the third elongate body, and a depth of the third elongate bodydefined between the anterior face and the posterior face of the thirdelongate body, the length of the third elongate body corresponding tothe lengths of the first and second elongate bodies, the width of thethird elongate body corresponding to the widths of the first and secondelongate bodies, and, along at least a portion of the correspondinglengths, the depth of the third elongate body exceeding the depth of thefirst and second elongate bodies.
 8. The method of claim 1, wherein thefirst rasp and the second rasp comprise femoral rasps, the first andsecond elongate bodies tapering distally, and the prosthetic implantcomprises a prosthetic femoral hip stem.
 9. A method of preparing asurgical patient's bone to receive a prosthetic implant, the methodcomprising the steps of: providing at least a first rasp having a firstelongate body with a geometry generally corresponding to the geometry ofthe prosthetic implant and a second rasp having a second elongate bodywith a geometry generally corresponding to the geometry of theprosthetic implant, each elongate body comprising a proximal end, adistal end, a medial face, a lateral face, an anterior face, and aposterior face, a length of each elongate body defined between theproximal end and the distal end of the elongate body, a width of eachelongate body defined between the medial face and the lateral face ofthe elongate body, and a depth of each elongate body defined between theanterior face and the posterior face of the elongate body, the length ofthe second elongate body corresponding to the length of the firstelongate body, the width of the second elongate body corresponding tothe width of the first elongate body, and, along at least a portion ofthe corresponding lengths, the depth of the second elongate bodyexceeding the depth of the first elongate body, whereby the secondelongate body is configured to contact more bone than the first elongatebody; and rasping the patient's bone with one of the first rasp and thesecond rasp, wherein the step of providing the first rasp comprisesproviding the first rasp having at least one essentially smooth face,whereby the at least one essentially smooth face lacks teeth extendingtherefrom, and wherein the first rasp comprises at least one groove, theat least one groove set into and interrupting the at least oneessentially smooth face of the first elongate body, whereby the depth ofthe first elongate body along the groove is less than the depth of thesecond elongate body along its corresponding length.
 10. The method ofclaim 9, wherein the at least one groove spans the at least oneessentially smooth face of the first elongate body.
 11. A method ofpreparing a surgical patient's bone to receive a prosthetic implant, themethod comprising the steps of: providing at least a first rasp having afirst elongate body with a geometry generally corresponding to thegeometry of the prosthetic implant and a second rasp having a secondelongate body with a geometry generally corresponding to the geometry ofthe prosthetic implant, each elongate body comprising a proximal end, adistal end, a medial face, a lateral face, an anterior face, and aposterior face, a length of each elongate body defined between theproximal end and the distal end of the elongate body, a width of eachelongate body defined between the medial face and the lateral face ofthe elongate body, and a depth of each elongate body defined between theanterior face and the posterior face of the elongate body, the length ofthe second elongate body corresponding to the length of the firstelongate body, the width of the second elongate body corresponding tothe width of the first elongate body, and, along at least a portion ofthe corresponding lengths, the depth of the second elongate bodyexceeding the depth of the first elongate body, whereby the secondelongate body is configured to contact more bone than the first elongatebody; and rasping the patient's bone with one of the first rasp and thesecond rasp; wherein the portion in which the depth of second elongatebody exceeds the depth of the first elongate body comprises at least onepointed tooth extending from the second elongate body and at least onerounded tooth extending from the first elongate body, whereby thepointed tooth extends further from the second elongate body than therounded tooth extends from the first elongate body.